Integrated multi-sensor control system and method

ABSTRACT

A GNSS integrated multi-sensor guidance system for a vehicle assembly includes a suite of sensor units, including a global navigation satellite system (GNSS) sensor unit comprising a receiver and an antenna. An inertial measurement unit (IMU) outputs vehicle dynamic information for combining with the output of the GNSS unit. A controller with a processor receives the outputs of the sensor suite and computes steering solutions, which are utilized by vehicle actuators, including an automatic steering control unit connected to the vehicle steering for guiding the vehicle. The processor is programmed to define multiple behavior-based automatons comprising self-operating entities in the guidance system, which perform respective behaviors using data output from one or more sensor units for achieving the behaviors. A GNSS integrated multi-sensor vehicle guidance method is also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

This application relates to U.S. Provisional Patent Application Ser. No.61/243,417, filed Sep. 17, 2009, filed concurrently herewith, which isincorporated herein by reference.

The present application is a reissue application of U.S. Pat. No.8,649,930, issued Feb. 11, 2014, entitled: GNSS INTEGRATED MULTI-SENSORCONTROL SYSTEM AND METHOD; which claims benefit of U.S. ProvisionalPatent Application No. 61/243,417, filed Sep. 17, 2009, the contents anddisclosures of which are hereby incorporated by reference in theirentireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a versatile integratedmulti-sensor apparatus which combines positional data from a variety ofsensor types including a GNSS system. The various sensor data is rankedaccording to its confidence level, and using that data as a means toautomatically create a planned path and steer a vehicle along thatplanned path. Elements of the present invention allow the system to beeasily interchangeable among a multitude of vehicles and to communicatewith other vehicles to allow for autonomous cooperative vehicle behaviorbuilding and task delegation.

2. Description of the Related Art

Global navigation satellite system (GNSS) guidance and control arewidely used for vehicle and personal navigation and a variety of otheruses involving precision location in geodesic reference systems. GNSS,which includes the Global Positioning System (GPS) and othersatellite-based positioning systems, has progressed to sub-centimeteraccuracy with known correction techniques, including a number ofcommercial satellite based augmentation systems (SBASs).

For even more accurate information, higher frequency signals withshorter wavelengths are required. It is known in the art that by usingGNSS satellites' carrier phase transmissions, and possibly carrier phasesignal components from base reference stations or satellite basedaugmentation systems (SBAS), including the Wide Area Augmentation System(WAAS) (U.S.), and similar systems such as EGNOS (European Union) andMSAS (Japan), a position may readily be determined to withinmillimeters. When accomplished with two antennas at a fixed spacing, anangular rotation may be computed using the position differences. In anexemplary embodiment, two antennas placed in the horizontal plane may beemployed to compute a heading (rotation about a vertical axis) from aposition displacement. Heading information, combined with position,either differentially corrected (DGPS) or carrier phase correctedreal-time kinematic (RTK), provides the feedback information desired fora proper control of the vehicle direction.

Another benefit achieved by incorporating a GNSS-based heading sensor isthe elimination or reduction of drift and biases resultant from agyro-only or other inertial sensor approach. Yet another advantage isthat heading may be computed while movable equipment is stopped ormoving slowly, which is not possible in a single-antenna, GNSS-basedapproach that requires a velocity vector to derive a heading. Yetanother advantage of incorporating a GNSS-based heading sensor isindependence from a host vehicle's sensors or additional externalsensors. Thus, such a system is readily maintained asequipment-independent and may be moved from one vehicle to another withminimal effort. Yet another exemplary embodiment of the sensor employsglobal navigation satellite system (GNSS) sensors and measurements toprovide accurate, reliable positioning information. GNSS sensorsinclude, but are not limited to, GPS, Global Navigation System (GLONAS),Wide Area Augmentation System (WAAS) and the like, as well ascombinations including at least one of the foregoing.

An example of a GNSS is the Global Positioning System (GPS) establishedby the United States government, which employs a constellation of 24 ormore satellites in well-defined orbits at an altitude of approximately26,500 km. These satellites continually transmit microwave L-band radiosignals in two frequency bands, centered at 1575.42 MHz and 1227.6 MHz,denoted as L1 and L2 respectively. These signals include timing patternsrelative to the satellite's onboard precision clock (which is keptsynchronized by a ground station) as well as a navigation message givingthe precise orbital positions of the satellites, an ionosphere model andother useful information. GPS receivers process the radio signals,computing ranges to the GPS satellites, and by triangulating theseranges, the GPS receiver determines its position and its internal clockerror.

In standalone GPS systems that determine a receiver's antenna positioncoordinates without reference to a nearby reference receiver, theprocess of position determination is subject to errors from a number ofsources. These include errors in the GPS satellite's clock reference,the location of the orbiting satellite, ionosphere induced propagationdelay errors, and troposphere refraction errors. The overall positionalsignal is weakened with each satellite target lost. These targets may belost due to obstructions such as trees, hills, or merely because thesatellite has orbited out of view.

To overcome these positioning errors of standalone GPS systems, manypositioning applications have made use of data from multiple GPSreceivers. Typically, in such applications, a reference or basereceiver, located at a reference site having known coordinates, receivesthe GPS satellite signals simultaneously with the receipt of signals bya remote or rover receiver. Depending on the separation distance betweenthe two GPS receivers, many of the errors mentioned above will affectthe satellite signals equally for the two receivers. By taking thedifference between signals received both at the reference site and theremote location, these errors are effectively eliminated. Thisfacilitates an accurate determination of the remote receiver'scoordinates relative to the reference receiver's coordinates. Additionalsensors may also be used to support weak GNSS positional data, such asan inertial measurement unit which may include a gyroscope. Suchadditional sensors are, however, prone to lose calibration and then needto be corrected.

Differential global navigation satellite system (DGNSS) guidanceutilizes a localized base receiver of known location in combination witha rover receiver on a moving vehicle for obtaining accurate vehiclepositions from GNSS data. Differential positioning, using base and roverreceivers, provides more accurate positioning information thanstandalone systems because the satellite ranging signal transmissionerrors tend to effect the base and rover receivers equally and thereforecan be cancelled out in computing position solutions. In other words,the base-rover position signal “differential” accurately places therover receiver “relative” to the base receiver. Because the “absolute”geo-reference location of the fixed-position base receiver is preciselyknown, the absolute position of the rover receiver can be computed usingthe base receiver known, absolute position and the position of the roverreceiver relative thereto.

Differential GPS is well known and exhibits many forms. GPS applicationshave been improved and enhanced by employing a broader array ofsatellites such as GNSS and WAAS. For example, see commonly assignedU.S. Pat. No. 6,469,663 to Whitehead et al. titled Method and System forGPS and WAAS Carrier Phase Measurements for Relative Positioning, datedOct. 22, 2002, the disclosures of which are incorporated by referenceherein in their entirely. Additionally, multiple receiver DGPS has beenenhanced by utilizing a single receiver to perform differentialcorrections. For example, see commonly assigned U.S. Pat. No. 6,397,147to Whitehead titled Relative GPS Positioning Using A Single GPS ReceiverWith Internally Generated Differential Correction Terms, dated May 28,2002 the disclosures of which are incorporated by reference herein intheir entireties.

It is not uncommon to utilize a GNSS system in combination with anautomatic-steering module linked to a vehicle's steering manifoldthrough a steering controller unit. The guidance unit receivespositional information from the GNSS unit and compares it with apre-planned path or map. Because the GNSS positional information allowsthe guidance unit to know exactly where the vehicle is located along apath, it can use this information to automatically guide and steer thevehicle along this path.

A steering controller is required to accept instructions from theguidance unit and actually perform the steering controls on the vehicle.This device connects to the vehicle steering manifold and/or hydraulicsteering valves. Signals from the guidance unit are delivered to thesteering controller, which then commands hydraulic valves to open orclose depending on the desired results.

Automatic steering systems using GNSS data tend to lose accuracy. If thesystem calibration is off the steering controller may tend toover-correct, resulting in erratic turns. Additionally, loss of the GNSSsignal could affect the automatic steering function.

SUMMARY OF THE INVENTION

Disclosed herein is a method for providing accurate and precise vehiclepositioning guidance and control with automatic steering capabilities.The present invention utilizes a series of separate sensors which mayserve as temporary reliable guidance devices when GNSS signals are weak,and are recalibrated when GNSS signals are strong. This reliablepositioning information gathering allows multiple vehicles to operate incooperation with each other using autonomous task delegation andcontrol. A versatile system is described that facilitates a number ofprecise steering tasks for a variety of functions using proportionalhydraulic control and state-of-the-art GNSS positional systems.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which illustrate the principles of thepresent invention and an exemplary embodiment thereof.

FIG. 1 is an isometric view of a tractor demonstrating the preferredembodiment.

FIG. 1A is an isometric view of a tractor demonstrating the three axesof orientation (X, Y and Z) and three possible directions of rotation(pitch, roll, and yaw).

FIG. 2 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 3 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 4 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 5 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 6 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 7 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 8 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 9 is an alternative line diagram demonstrating the relationshipbetween devices in an embodiment of the invention.

FIG. 10 is a line diagram demonstrating the step-by-step method by whichthe sensor suite determines confidence levels of various sensors.

FIGS. 11A-G demonstrate various path-finding, path-creating, and objectavoidance possibilities available when a tractor is equipped with thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED ASPECTS

I. Introduction, Environment, and Preferred Embodiment

Generally, a preferred embodiment of the present invention consists ofcomponents which allow a farming vehicle, with or without an attachedfarming implement, to automatically guide itself around a field andperform a plurality of functions, leading to precision farming. Saidvehicle may be in constant communication with other vehicles similarlyequipped for the same or different tasks. The vehicles within such anetwork are capable of making decisions amongst themselves about whereto go and what to do to best perform assigned tasks based on the globalposition of each vehicle relative to each other and the location of saidtasks.

The preferred embodiment or the integrated multi-sensor guidance system(guidance system) 2, as shown in FIG. 1, includes a vehicle 4, which maybe equipped with a farming implement 6, a sensor suite 7, a guidanceunit 10 capable of versatile path guidance, a steering controller 12providing proportional hydraulic control, a hydraulic steering manifold14, a wheel angle/speed sensor (WAS) 16, and an implement steeringmanifold 50. Additionally, the guidance system 2 includes a base stationantenna 18 to communicate with a differential receiver 20, a GNSSreceiver 22 connected to a plurality of antennas 24 located on thevehicle 4, and an inertial measurement unit (IMU) 26 for providingadditional information to said guidance unit 10. Also included is a userinterface 28 within the cab of the vehicle 4 allowing the driver of thatvehicle to manually input commands into the guidance system 2 andoverride automatic control.

The preferred embodiment of the present invention has at least fourparticular applications. First, there is a command center approach thatcan be applied, where the guidance system is a one-time capitalinvestment that can be moved and used with each piece of farmingequipment, regardless of the season or the task being performed. Second,a highly accurate yet economical automatic steering application isavailable. Such an application can allow for high accuracy work to beperformed 24 hours a day, 7 days a week with limited stress on humandrivers. The third particular application of the present invention dealswith sectional control of implements; that is the guidance unit canselectively shut off portions of the working implement where overlapwould otherwise occur. Finally, site-specific farming using variablerate control can be applied. Depending on the site and the crop beinggrown, the system can fluctuate how much work the implement does,whether that be spraying, seeding, or tilling.

FIGS. 11A-G demonstrate the versatility of the automatic steeringcapabilities of the present invention on straight, contour, and circlepivot driving paths. These figures demonstrate a vehicle beingself-driven around a series of different path-types 64 which areautomatically generated by the guidance system 10 of the preferredembodiment due to information both manually input and gathered by thesensor suite 7. These figures demonstrate how the guidance system 2 willrecognize field borders 62 and obstacles 66. When the planned path 64encounters the obstacles 66, the system will either automatically createan alternative path 72 or return manual control to the vehicle driver.When the planned path 64 encounters the field border 62, the system willautomatically shut off all implement controls and either perform anautomatic turn in the headlands 68 or return manual vehicle control tothe vehicle operator.

II. Sensor Suite

The sensor suite 7 is comprised of a plurality of sensors, including atleast a GNSS system 8, a wheel angle sensor (WAS) 16 and an inertialmeasurement unit (IMU) 26. Additional sensors may include a video cameraunit oriented in the vehicle towards the direction of travel. Forexample, the video camera unit can be oriented towards a landmark on thehorizon, which can provide an aiming point or point of referencecorresponding to a predetermined geo-reference location. Other sensorsin the sensor suite 7 can include a radar unit for ranging and directionfinding, e.g., to a particular radar target. A laser unit, radio input,telemetry, and other sensor units capable of aiding in precisionposition and trajectory mapping can also be utilized. This suite ofsensors gathers position and heading data and relay this information tothe guidance unit 10 discussed in detail in section III.

In the preferred embodiment of this invention, the GNSS system 8 will beassigned the highest confidence level as a default, and is thus aprimary and important element to this guidance system 2. Globalnavigation satellite systems (GNSS) are broadly defined to include GPS(U.S.), Galileo (proposed), GLONASS (Russia), Beidou/Compass (China,proposed), IRNSS (India, proposed), QZSS (Japan, proposed) and othercurrent and future positioning technology using signals from satellites,with or without augmentation from terrestrial sources. Inertialnavigation systems (INS) include gyroscopic (gyro) sensors,accelerometers and similar technologies for providing outputcorresponding to the inertia of moving components in all axes, i.e.through six degrees of freedom (positive and negative directions alongtransverse X, longitudinal Y and vertical Z axes). Yaw, pitch and rollrefer to moving component rotation about the Z, X and Y axesrespectively. Said terminology will include the words specificallymentioned, derivatives thereof and words of similar meaning.

Disclosed herein in an exemplary embodiment is a sensor system forvehicle guidance. The sensor system can utilize a plurality of GNSS codeor carrier phase differenced antennas to derive attitude information,herein referred to as a GNSS attitude system. Moreover, the GNSSattitude system may optionally be combined with one or more rate gyro(s)used to measure turn, roll or pitch rates and to further calibrate biasand scale factor errors within these gyros. In an exemplary embodiment,the rate gyros and GNSS receiver/antenna are integrated together withinthe same unit, to provide multiple mechanisms to characterize avehicle's motion and position to make a robust vehicle steering controlmechanism.

The preferred embodiment of the present invention includes a vehicle 4,an implement 6, and a sensor suite 7. The sensor suite is comprised of aplurality of sensors, containing at least a GNSS system 8, a WAS 16, andan IMU 26. Said GNSS system 8 is further comprised of a receiver 22, adifferential receiver 20, a base station antenna 18, and a plurality ofantennas 24 located on said vehicle 4 and implement 6. The GNSS systemprovides position information to the guidance unit 10. This informationcan be used or creating a path 64 around a field 60, establishingalternatives 72 to said path when obstacles 66 are encountered.

The sensor suite 7 will integrate all connected sensors with theultimate result being robust tight wheel control; that is, wheel andvehicle control at a very precise level. This sensor integrationimplements a confidence level or reliance level checklist by whichcertain sensors are given higher-priority when position information isused unless those sensors are reporting weak or no signal. Higherpriority sensor systems are used to recalibrate lower priority systemswhile said higher priority systems remain at their default signallevels. This ensures that when the higher priority systems lose signal,the lower priority systems are timely calibrated to compensate for thehigher priority system for the short time period of reduced signal.

III. Guidance Unit 10

A guidance unit 10, otherwise known as an electronic control unit (ECU),can be put to several different uses on an agricultural vehicle. Onecommon use is to provide heading data based on a pre-planned orcalculated path 64. The guidance unit might have the path manually inputinto the unit, or it might be capable of receiving GNSS positional dataand information regarding a particular piece of land and calculate apath based off of this information. The guidance unit 10 can displayinformation to the vehicle's driver through a user interface (UI) 28 andallow the driver to manually steer the vehicle along the displayed path.A more precise application of such a guidance unit 10 is to introduceautomatic steering to a farming vehicle 4. The vehicle 4 will then guideitself along said calculated or pre-planned path 64 with greaterprecision than manual steering could provide.

The guidance unit 10 can be put to additional uses as well, includingautomated implement control and advanced mapping and data management.The automated implement control comprises sectional implement control,including application rate control and variable rate control. Theadvanced mapping and data management, as mentioned above, includes thesystem's ability to take known landscape information from the GNSSsystem and store that information for processing during jobs. This leadsto real-time map creation as the vehicle self-guides the piece of landto be worked.

The preferred embodiment of the present invention includes the sensorsuite 7 mentioned above which is connected to the guidance unit 10. Theguidance unit 10 interprets positional data received from the sensorsuite 7 and puts it to use in several ways. The guidance unit 10 isfurther divided into at least a logic portion 30 and a guidance portion32. The guidance unit receives data from the sensor suite 7, determineswhat to do with the data in the logic portion 30, including computing apath 64 or selectively controlling the implement, and then transmitsthat data through the guidance portion 32 to the steering controller 12and the implement steering controller 50.

As demonstrated in FIG. 10, a confidence loop 100 is employed by theguidance unit 10 against multiple sensors in the sensor suite 7 todetermine which sensor systems should be relied on when determiningposition and heading information. The confidence loop 100 is comprisedof several steps. The start step 102 is initiated when the guidancesystem 2 is booted up. This can either be directly connected to thestart-up of the vehicle 4 to which the system is attached, or completelyindependent of that vehicle. The system is then initialized at 104 and adefault process 106 is begun. In this default process, the sensorsystems are placed in a default reliance list whereby a particularsensor is given a higher confidence than other sensors and thathigh-confidence sensor is used to calibrate all other sensors. Thishighest confidence sensor is also used for initial position and headinginformation gathering and to instruct the guidance unit 10. In apreferred embodiment of the invention, the GNSS system 8 could delimitas the initial highest confidence system, followed by the IMU 26 and theWAS 16.

Once the default process 106 is begun, the loop 100 begins a sensorsignal check 108. During this step, each sensor's signal is checkedinternally to determine whether it is communicating properly with therest of the guidance system 2 and whether incoming signals are present.For example, the GNSS system 8 will be checked several times per secondto determine the strength of the satellite signal being received by theantennas 24 and receiver 22. These sensor signal levels are thencompared 110 with the default signal levels that are expected. If thesedetected signals are equal to or exceed the strength of the expectedsignal, a “yes” command is entered and the sensor signal check beginsagain.

If, however, the detected signal is lower than the expected defaultsignal, a “no” command is reported and the loop 100 enters a confidencelevel reduction step 112 whereby the particular sensor's confidencelevel is reduced according to the strength of the detected signal. Aconfidence level comparison step 114 is then performed, comparing theupdated confidence levels of all sensors in the sensor suite 7. If theresult of the sensor-reliance reordering step 116 is a change inreliance levels, a “yes” command is returned and the reliance prioritylist is reordered at 118. This occurs when the confidence level of aparticular sensor drops so low due to a weak or loss of signal that itsinformation is no longer reliable. That sensor drops down in thereliance list and the new most reliable sensor is used to produceposition and heading information until a sensor signal check 108 resultsin the original sensor regaining its signal and thus priority level. Ifthe result of the sensor-reliance reordering step 116 is “no,” then thereliance list is not reordered and the confidence loop 100 returns tothe sensor signal checking step 104.

This process of steps ensures that only the most reliable sensors areused to determine current vehicle position and heading and torecalibrate less reliable sensors. The listed steps are an example ofsuch a confidence loop 100 and are not intended to be the only means toachieve the desired results. Additional or fewer steps may be used toreturn an appropriate confidence or reliance level list.

As an example of this process, the guidance unit 10 is connected to thesteering controller 12 and the WAS 16. The guidance unit can relaycorrection information from the GNSS positioning system 8 to the WAS forcalibration purposes. The WAS 16 is initially calibrated with azero-heading and receives information from the steering controller 12regarding turn data, and in turn relays actual data back to the steeringcontroller and the guidance unit. The guidance unit knows exact positionand heading information because of data received from the GNSS system 8and other sensors high on the reliability list. By comparing the highlyreliable GNSS information with the less reliable WAS information, theguidance unit can tell whether the WAS is correct or not. If it isdetermined that the WAS information is incorrect, the guidance unit canrecalibrate the WAS and create a new zero-heading. In the alternative,if the confidence loop 100 were to determine that the GNSS system 8 hada weak signal at a particular point, the guidance unit 10 could rely ondata from the IMU 26 and/or WAS 16 until the GNSS signal returns. Theseadditional sensors are better suited for short-term accurate guidance,but quickly degrade and must be recalibrated.

IV. Steering Controller 12

The steering controller 12 is the third major component of the guidancesystem 2. The steering controller is designed to accept guidance inputsand transform those inputs into outputs that result in actual motion andsteering of the vehicle 4.

The steering controller 12 portion of the guidance system 2 is designedto transmit and receive steering information from all associated partsand to provide the means for actually controlling the direction of thevehicle 4 based upon position and guidance data gathered by the sensorsuite 7 and interpreted by the guidance unit 10. The steering controlleris directly connected to the guidance unit 10, the WAS 16, the hydraulicsteering manifold 14, and the implement controller 50. The steeringcontroller 12 is the primary step for transforming data from theguidance system into actual movement of the vehicle itself.

Although the WAS 16 is part of the sensor suite 7 as discussed above,there is a direct connection between the WAS 16 and the steeringcontroller 12. This results in a “wheel loop” whereby the steeringcontroller 12 transmits steering commands to the hydraulic steeringmanifold 14 which proceeds to turn the wheels of the vehicle 4 in adirection. The angle of the turn is reported back to the steeringcontroller, which may order further steering corrections depending onthe pre-planned path 64. This angle can also reported to the guidanceunit 10 where it is compared with other sensors in the confidence loop100. Assuming another sensor, such as the GNSS system 8, is currently atthe top of the reliance list, the WAS may be recalibrated if it turnsout that the applied turning angle was incorrect when applied to thecalculated path 64.

V. Automaton Control

The process of controlling several machines as automatons in a smart andaccurate system, such as the one presented herein, is accomplished withthe combination of the above-described units into a single, autonomoussystem allowing one system to control the positioning, guidance, andworkload of a fleet of agricultural vehicles.

VI. Alternative Examples of a Guidance System 2

The above sections discuss the preferred embodiment of the invention,comprising generally a sensor suite 7, a guidance unit 10 and a steeringcontroller 12. Several alternative methods of forming the guidancesystem 2 exist. A primary example is using the GNSS system 8 tocompletely replace the sensor suite 7, and moving the IMU 26 to theguidance unit 10. Other examples of said guidance system 2 follow.

As shown in FIG. 3, the IMU 26 and an optional “smart” antenna 34 may bedirectly connected to the guidance unit 10 providing direct informationused to compare position and heading information with data received fromthe sensor suite 7. The smart antenna 34 is a combination receiver 22and antenna 24. The user interface (UI) 28 is connected directly to theGNSS system 8. Additionally, the WAS 16 is connected separately andentirely to the steering controller 12.

FIG. 4 provides another detailed breakdown of the guidance unit 10 andits relationship with a GNSS system 8 and the steering controller 12.The IMU 26 is composed of a plurality of Kalman filters 36 which relayinformation regarding the various degrees of pitch, roll, and heading ofthe vehicle. The guidance portion 32 is further composed of across-track PID 38, a state dependent Ricatti equation (SDRE) 40 and aheading proportional integral derivative (PID) component 42. Thesteering controller 12 is again in direct communication with the WAS 16.

FIG. 5 demonstrates another alternative example of the relationshipbetween the guidance unit 10 and the other elements of the guidancesystem 2. In this example the guidance unit 10 is independentlyconnected to several unique elements, including a GNSS system 8, animplement control system 50, a variable rate transfer controller 52,personal computer office software 44, and a steering controller 12. Thesteering controller is separately connected to steering sensors 46 andthe steering interface 48. The steering sensors may in turn contain WAS16 or other sensor types. An important aspect demonstrated in thisfigure is the relationship between the guidance unit 10 and cooperativePC office software 44. This relationship is a key element because itallows the guidance unit 10 to be updated, controlled, and calibratedthrough a connection with a standard office PC. This allows the end-userto create paths, identify field boundaries, and update equipmentsoftware while using familiar PC technology instead of new,single-application user interfaces associated solely with the guidanceunit.

FIG. 6 demonstrates another alternative example of the presentinvention. In this example, the guidance unit 10 contains a majority ofthe standard system elements, including the GNSS system 8, a UI 28, avariable rate controller 52, guidance 32 and steering 46 sensors, anaccessory input 54, a mapping device 56, and a section controller 58containing input/output connections. The accessory input device 54allows the guidance controller to connect to external devices such as aweather radio, wireless service, video sensors, and monitoring devices.A wireless receiver 22 is connected to the GNSS 8 portion of theguidance unit 10 externally. A steering controller 12 is also connectedto the guidance 32 and steering 46 sensors externally. The steeringcontroller has additional connections to control the vehicle steeringmanifold 14.

FIG. 8 demonstrates another alternative example of the presentinvention. As is typical, the guidance unit 10 is the central element.Two steering controllers 12 are connected to the guidance unit,providing options to the guidance unit. A smart antenna 34, UI 28, andGNSS 8 system are connected to the guidance unit 10 along a firstconnection, and a second GNSS 8 system, along with a virtual terminal(VT) and/or an original equipment manufacturer (OEM) terminal. These twoconnections again provide options upon which the guidance unit 10 canmake decisions to base path-making and steering choices on.

FIG. 9 demonstrates another example of the present invention generallycomprising a kit for installation in an existing vehicle, such as atractor with a hydraulic steering system. This example is again dividedinto three main components; the GNSS system 8, the guidance unit 10, andthe steering controller 12. The GNSS system 8 includes an internalreceiver 22 and at least one external antenna 24, along with variousinput/output connections. A CAN connection links the GNSS system 8 tothe guidance unit 10. The guidance unit includes an internal IMU and anoptional connection to an external smart antenna 34. The guidance unit10 connects to the steering controller 12 through another CANconnection. The steering controller 12 is connected to and controls thevehicle steering valve/manifold 14. An analog connection links the WASto the steering controller 12. Additionally, several switches areconnected to the steering controller that will cancel auto-steer andreturn the vehicle to manual steering, stopping the vehicle immediatelyunless the driver is ready to continue. These switches include, but arenot limited to, a steering wheel switch that detects when the operator'shand touches the steering wheel, a magnetic shutoff switch that isattached to the operator's seat and can determine if and when theoperator stands to leave the seat, and a manual shut-off switch.

An integrated multi-sensor guidance system for a vehicle assemblyincluding a steering subsystem, which guidance system includes: saidvehicle assembly having a dynamic attitude comprising a geo-referencelocation, vehicle assembly orientation and vehicle assembly speed; aprocessor with multiple sensor inputs and actuator outputs; a suite ofsensor units each connected to a respective sensor input.

Said sensor unit suite includes a GNSS unit with an antenna and areceiver connected to said antenna, said GNSS unit providing outputsignals corresponding to the GNSS-defined locations of said vehicleassembly dynamic attitude to a respective processor input.

A guidance controller is adapted for receiving signal input andgenerating control output based on said signal input; a data storagedevice including memory storage; and a suite of actuator units eachconnected to a respective actuator output.

Said sensor unit suite includes an inertial measurement unit (IMU)sensor providing output signals corresponding to an inertial aspect of adynamic attitude of said vehicle assembly to a respective processorinput.

Said guidance controller is adapted for receiving inertial measurementsignals and integrating said inertial measurement signals with saidGNSS-based positioning signals. Said processor is programmed todetermine variable confidence levels in real time for each said sensorunit based on its current relative performance; and said processor isprogrammed to utilize said sensor unit outputs proportionally based ontheir respective confidence levels in generating said control outputsignals.

Said processor is programmed to define multiple behavior-basedautomatons comprising self-operating entities in said guidance system,said automatons performing respective behaviors using data output fromone or more sensor units for achieving said behaviors and wherein one ormore sensor units provide the same or similar data.

Each said automaton has an accepting interface for accepting requestsfrom other automatons; a requesting interface for making requests toanother automaton; a knowledge input for receiving a behavioraldefinition for affecting the behavior of the automatons; and a datainput for receiving input data; and a data output for sending out thedata.

Said actuator unit suite includes a steering unit connected to saidsteering subsystem and receiving said control output signals from saidprocessor. Said steering subsystem includes: a steering controllerincluding a steering processor and connected to said guidancecontroller. Said steering controller receives guidance signals as inputsfrom said guidance controller and computing steering signals as outputsfrom said steering controller; and said steering actuator receives saidsteering signals from said steering controller and steering said vehiclein response thereto.

Said sensor suite includes sensor units chosen from among the groupcomprising: a video camera unit oriented in the vehicle assemblydirection of travel; a radar unit; a laser unit; radio input; telemetry;material application exclusion areas input; satellite image inputs;contour/elevation overlay inputs; prescription mapping; and a wheelangle sensor (WAS).

Said actuator suite includes actuator units chosen from among the groupcomprising: an implement steering unit, an implement sectional controlunit, personal computer (PC) office software, material application ratecontrol, secondary vehicle control, mapping, crop yield, and mappingskips and overlaps.

Said guidance controller is adapted for receiving and storing in saidmemory storage device GNSS-based positioning signals. Said processor isadapted for computing a GNSS-based guide pattern. Said guidancecontroller is adapted for providing output signals to a display devicefor displaying vehicle motion relative to guide patterns and contrastingdisplays of areas treated by said vehicle along previously-traveledportions of said guide patterns. Said guidance controller is adapted forcalibrating and storing in said memory multiple vehicle profiles, eachsaid profile including multiple, independent vehicle-specificautomatons.

A method of vehicle control and guidance, comprises the steps: providinga vehicle assembly including a steering subsystem and dynamic attitudecomprising a geo-reference location, vehicle assembly orientation, andvehicle assembly speed; providing a guidance system including processorwith multiple sensor inputs and actuator outputs, a suite of sensorunits connected to a respective sensor input, a suite of actuator unitsconnected to a respective actuator output, and a data storage deviceincluding memory storage; providing a guidance controller; inputtingsignal input data to said guidance controller; and generating controloutput signals with said guidance controller based on said signal input.

The sensor unit suite includes an inertial measurement unit (IMU) sensorproviding output signals corresponding to an inertial aspect of adynamic attitude of said vehicle assembly to a respective processorinput. The method of vehicle control and guidance also includesgenerating inertial measurement signals with said IMU sensor; receivingthe inertial measurement signals with said guidance controller; andintegrating said inertial measurement signals with said GNSS-basedpositioning signals.

The method of vehicle control and guidance also includes determiningvariable confidence levels with the processor in real time for each saidsensor unit based on current relative performance; and utilizing saidsensor unit outputs proportionally based on the respective confidencelevels in generating said control output signals.

The method of vehicle control and guidance also includes definingmultiple behavior-based automatons comprising self-operating entities insaid guidance system; and instructing said automatons to performrespective behaviors using data output from one or more sensor units forachieving said behaviors wherein one or more sensor units provide thesame or similar data.

The method of vehicle control and guidance also includes providing eachautomaton with an accepting interface for accepting requests from otherautomatons; providing each automaton with a requesting interface formaking requests to another automaton; providing each automaton with aknowledge input for receiving a behavioral definition for affecting thebehavior of the automatons; providing each automaton with a data inputfor receiving input data; and providing each automaton with a dataoutput for sending data.

The method of vehicle control and guidance also includes providing asteering unit connected to said steering subsystem; and receiving saidcontrol output signals at said steering unit as steering controlinstructions. The method of vehicle control and guidance also includesproviding a steering processor connected to said guidance controller;receiving guidance signals at said steering controller as inputs fromsaid guidance controller; computing steering signals as outputs fromsaid steering controller; receiving said steering signals with saidsteering actuator; and steering said vehicle assembly in response tosaid steering signals.

The method of vehicle control and guidance also includes determiningvariable confidence levels with the processor in real time for each saidsensor unit based on current relative performance; and utilizing saidsensor unit outputs proportionally based on the respective confidencelevels in generating said control output signals.

An integrated multi-sensor guidance system for a vehicle assemblyincluding a steering subsystem, includes: said vehicle assembly having adynamic attitude comprising a geo-reference location, vehicle assemblyorientation and vehicle assembly speed; a processor with multiple sensorinputs and actuator outputs; a suite of sensor units each connected to arespective sensor input.

Said sensor unit suite includes a GNSS unit with an antenna and areceiver connected to said antenna, said GNSS unit provides outputsignals corresponding to the GNSS-defined locations of said vehicleassembly dynamic attitude to a respective processor input; said sensorunit suite includes an inertial measurement unit (IMU) sensor providingoutput signals corresponding to an inertial aspect of a dynamic attitudeof said vehicle assembly to a respective processor input.

Said guidance controller is adapted for receiving inertial measurementsignals and integrating said inertial measurement signals with saidGNSS-based positioning signals; said processor is programmed todetermine variable confidence levels in real time for each said sensorunit based on its current relative performance.

Said processor is programmed to utilize said sensor unit outputsproportionally based on their respective confidence levels in generatingsaid steering signals; a suite of actuator units are each connected to arespective actuator output; said actuator unit suite includes a steeringunit connected to said steering subsystem and receiving said steeringsignals from said processor.

Said processor is programmed to define multiple behavior-basedautomatons comprising self-operating entities in said guidance system,said automatons performing respective behaviors using data output fromone or more sensor units for achieving said behaviors and wherein one ormore sensor units provide the same or similar data.

Each said automaton has an accepting interface for accepting requestsfrom other automatons; a requesting interface for making requests toanother automatons; a knowledge input for receiving a behavioraldefinition for affecting the behavior of the automatons; a data inputfor receiving input data; and a data output for sending out the data.

It will be appreciated that the components of the system 2 can be usedfor various other applications. Moreover, the subsystems, units andcomponents of the system 2 can be combined in various configurationswithin the scope of the present invention. For example, the variousunits could be combined or subdivided as appropriate for particularapplications. The system 2 is scalable as necessary for applications ofvarious complexities. It is to be understood that while certain aspectsof the disclosed subject matter have been shown and described, thedisclosed subject matter is not limited thereto and encompasses variousother embodiments and aspects.

Having thus described the disclosed subject matter, what is claimed asnew and desired to be secured by Letters Patent is:
 1. An integratedmulti-sensor guidance system for a vehicle assembly including a steeringsubsystem, which guidance system includes: said vehicle assembly havinga dynamic attitude comprising a geo-reference location, vehicle assemblyorientation and vehicle assembly speed; a processor with multiple sensorinputs and actuator outputs; a suite of sensor units each connected to arespective sensor input; said sensor unit suite includes a GNSS unitwith an antenna and a receiver connected to said antenna, a wheel anglesensor unit (WAS), and an inertial measurement unit (IMU) sensor, saidGNSS unit providing output signals corresponding to the GNSS-definedlocations of said vehicle assembly dynamic attitude to a respectiveprocessor input; a guidance controller adapted for receiving signalinput and generating control output based on said signal input; a datastorage device including memory storage; a suite of actuator units eachconnected to a respective actuator output; said guidance controllerbeing adapted for receiving and storing in said memory storage deviceGNSS-based positioning signals; said processor being adapted forcomputing a GNSS-based. guide pattern; said guidance controller beingadapted for providing output signals to a display device for displayingvehicle motion relative to guide patterns and contrasting displays ofareas treated by said vehicle along previously-traveled portions of saidguide patterns; said guidance controller being adapted for calibratingand storing in said memory multiple vehicle profiles, each said profileincluding multiple, independent vehicle-specific automatons; anaccepting interface for accepting requests from other automatons; arequesting interface for making requests to another automaton; aknowledge input for receiving a behavioral definition for affecting thebehavior of the automatons; a data input for receiving input data; adata output for sending output data; said processor programmed todetermine different variable confidence levels in real time for each ofsaid sensor GNSS unit, WAS, and IMU sensor based on its current relativeperformance; said processor programmed to utilize said sensor GNSS unit,WAS, and IMU sensor outputs proportionally based on their respectiveconfidence levels in generating said control output signals; and whereinsaid processor is programmed to define multiple behavior-basedautomatons comprising self-operating entities in said guidance system,said automatons performing respective behaviors using data output fromsaid one or more sensor units GNSS unit, said WAS, and said IMU sensorfor achieving said behaviors and wherein said one or more sensor unitsGNSS unit, WAS, and IMU sensor provide at least some of the same orsimilar data.
 2. The guidance system as claimed in claim 1, wherein saidsensor unit suite includes an inertial measurement unit (IMU) sensorproviding output signals corresponding to an inertial aspect of adynamic attitude of said vehicle assembly to a respective processorinput said guidance controller sends steering control instructionsinstructing said automatons to perform respective behaviors using dataoutput from one or more GNSS unit, WAS, and IMU sensor.
 3. The guidancesystem as claimed in claim 2 1, wherein said guidance controller isadapted for receiving inertial measurement signals from the IMU andintegrating said inertial measurement signals with said GNSS-basedpositioning signals.
 4. The guidance system as claimed in claim 1,wherein said. actuator unit suite includes a steering unit connected tosaid steering subsystem and receiving said control output signals fromsaid processor.
 5. The guidance system as claimed in claim 4, whereinsaid steering subsystem includes: a steering controller including asteering processor and connected to said guidance controller; saidsteering controller receiving guidance signals as inputs from saidguidance controller and computing steering signals as outputs from saidsteering controller; and said steering actuator receiving said steeringsignals from said steering controller and steering said vehicle inresponse thereto.
 6. The guidance system as claimed in claim 1, whereinsaid sensor suite includes sensor units chosen from among the groupcomprising: a video camera unit oriented in the vehicle assemblydirection of travel; a radar unit; a laser unit; radio input; telemetry;material application exclusion areas input; satellite image inputs; andcontour/elevation overlay inputs; prescription mapping; and a wheelangle sensor (WAS).
 7. The guidance system as claimed in claim 1,wherein said actuator suite includes actuator units chosen from amongthe group comprising: an implement steering unit, an implement sectionalcontrol unit, personal computer (PC) office software, materialapplication rate control, secondary vehicle control, mapping, cropyield, and mapping skips and overlaps.
 8. A method of vehicle controland guidance, which method comprises the steps: providing a vehicleassembly including a steering subsystem and dynamic attitude comprisinga geo-reference location, vehicle assembly orientation, and vehicleassembly speed; providing a guidance system including a processor withmultiple sensor inputs and actuator outputs, a suite of sensor unitsconnected to a respective sensor input, a suite of actuator unitsconnected to a respective actuator output, and a data storage deviceincluding memory storage; providing a guidance controller; inputtingsignal input data to said guidance controller; generating control outputsignals with said guidance controller based on said signal input;receiving and storing in said memory storage device GNSS-basedpositioning signals with said guidance controller; computing aGNSS-based guide pattern with said processor; providing output signalswith said guidance controller to a display device for displaying vehiclemotion relative to guide patterns and contrasting displays of areastreated by said vehicle along previously-traveled portions of said guidepatterns; calibrating and storing in said memory multiple vehicleprofiles with said guidance controller, each said profile includingmultiple, independent vehicle-specific automatons; wherein said sensorunit suite includes an inertial measurement unit (IMU) sensor providingoutput signals corresponding to an inertial aspect of a dynamic attitudeof said vehicle assembly to a respective processor input; generatinginertial measurement signals with said IMU sensor; receiving theinertial measurement signals with said guidance controller; integratingsaid inertial measurement signals with said GNSS-based positioningsignals; defining multiple behavior-based automatons comprisingself-operating entities in said guidance system; instructing saidautomatons to perform respective behaviors using data output from one ormore sensor units for achieving said behaviors wherein one or inuresensor units provide the same or similar data; providing each automatonwith an accepting interface for accepting requests from otherautomatons; providing each automaton with a requesting interface formaking requests to another automaton; providing each automaton with aknowledge input for receiving a behavioral definition for affecting thebehavior of the automatons; providing each automaton with a data inputfor receiving input data; providing each automaton with a data outputfor sending data; requesting instructions by each automaton from eachother automaton; and accepting instructions by each automaton providedfrom each other automaton.
 9. A method of vehicle control and guidanceas claimed by claim 8, including the steps: determining variableconfidence levels with the processor in real time for each said sensorunit based on current relative performance; and utilizing said sensorunit outputs proportionally based on the respective confidence levels ingenerating said control output signals.
 10. A method of vehicle controland guidance as claimed by claim 8, including the steps: providing asteering unit connected to said steering system; and receiving saidcontrol output signals at said steering unit as steering controlinstructions.
 11. A method of vehicle control and guidance as claimed byclaim 10, including the steps: providing a steering processor connectedto said guidance controller; receiving guidance signals at said steeringcontroller as inputs from said guidance controller; computing steeringsignals as outputs from said steering controller; receiving saidsteering signals with said steering actuator; and steering said vehicleassembly in response to said steering signals.
 12. An integratedmulti-sensor guidance system for a vehicle assembly including a steeringsubsystem, which guidance system includes, comprising: said vehicleassembly having a dynamic attitude comprising a geo-reference location,vehicle assembly orientation and vehicle assembly speed; a processorwith multiple sensor inputs and actuator outputs; a suite of sensorunits each connected to a respective sensor input; said sensor unitsuite including a GNSS unit with an antenna and a receiver connected tosaid antenna, said GNSS unit providing output signals corresponding tothe GNSS-defined locations of said vehicle assembly dynamic attitude toa respective processor input; said sensor unit suite including aninertial measurement unit (IMU) sensor providing output signalscorresponding to an inertial aspect of a dynamic altitude of saidvehicle assembly to a respective processor input; said guidancecontroller being adapted for receiving said inertial measurement signalsand integrating said inertial measurement signals with said GNSS-basedpositioning signals; said processor being programmed to determinevariable confidence levels in real time for each said sensor unit basedon its current relative performance; said processor being programmed toutilize said sensor unit outputs proportionally based on theirrespective confidence levels in generating said steering signals; asuite of actuator units each connected to a respective actuator output;said actuator unit suite including a steering unit connected to saidsteering subsystem and receiving said steering signals from saidprocessor; said processor being programmed to define multiplebehavior-based automatons comprising self-operating entities in saidguidance system, said automatons performing respective behaviors usingdata output from one or more said sensor units for achieving saidbehaviors and wherein said one or more sensor units provide the same orsimilar data; each said automaton having: an accepting interface foraccepting requests from other automatons; a requesting interface formaking requests to another automatons; a knowledge input for receiving abehavioral definition for affecting the behavior of the automatons; adata input for receiving input data; and a data output for sending outthe data; said guidance controller being adapted for receiving andstoringthe same or another processor further configured to: receive andstore in said a memory storage device global navigation satellite system(GNSS)-based positioning signals and inertial measurement signals froman inertial measurement unit (IMU) sensor; said processor being adaptedfor computingcompute a GNSS-based guide pattern; said guidancecontroller being adapted for providingprovide output signals to adisplay device for displayingto display vehicle motion for the vehiclerelative to guide patternsthe guide pattern and contrastingto contrastdisplays of areas treated by saidthe vehicle along previously-traveledportions of saidthe guide patternspattern; and said guidance controllerbeing adapted for calibrating and storingcalibrate and store in saidthememory storage device multiple vehicle profiles, each said profileincluding multiple, independent vehicle-specific automatons.
 13. Aguidance system for operating multiple vehicles, the guidance systemincluding a guidance controller to: receive and store in a memorystorage device data from sensor units located on a first vehicleincluding velocity, acceleration and GNSS-based position data derivedfrom a wheel angle sensor (WAS), inertial measurement unit (IMU), andglobal navigation satellite system (GNSS); determine variable confidencelevels in real time the said sensor units based on its current relativeperformance; define multiple behavior-based automatons comprisingself-operating entities in said guidance system, said automatonsperforming respective behaviors using data output from said one or moresensor units for achieving said behaviors and wherein said one or moresensor units provide the same or similar data; each said automatonhaving: an accepting interface for accepting requests from otherautomatons; a requesting interface for making requests to anotherautomatons; a knowledge input for receiving a behavioral definition foraffecting the behavior of the automatons; a data input for receivinginput data; and a data output for sending out the data; calibrate andstore in the memory storage device multiple vehicle profiles, each saidprofile including multiple, independent vehicle-specific automatons;compute a guide path for the first vehicle from at least the GNSS-basedposition data; send the GNSS-based position data to a display device todisplay movement of the first vehicle relative to the guide path;provide output signals to the display device to display vehicle motionfor the first vehicle relative to the guide path and to contrastdisplays of areas treated by the first vehicle along previously-traveledportions of the guide path; store in the memory storage device a vehicleprofile for a second vehicle; send guidance instructions to the secondvehicle to use data output from one or more of the sensor units thatprovide the same position data as derived from the GNSS, WAS, and IMU tocontrol movement of the second vehicle in cooperation with movement ofthe first vehicle along the guide path; and update the guidanceinstructions to the second vehicle based on computed differences in theposition data of the first vehicle.
 14. An integrated multi-sensorguidance system comprising a guidance controller to: receive signalsfrom different sensor units including a global navigation satellitesystem (GNSS)-based sensor unit, a wheel angle sensor (WAS), and aninertial measurement unit (IMU) sensor providing positions for avehicle; define multiple behavior-based automatons comprisingself-operating entities in said guidance system performing respectivebehaviors using data output from the sensor units and wherein saidsensor units provide at least some same or similar data, each saidautomaton having: an accepting interface for accepting requests fromother automatons; a requesting interface for making requests to anotherautomatons; a knowledge input for receiving a behavioral definition foraffecting the behavior of the automatons; a data input for receivinginput data; and a data output for sending out the data; calibrate andstore in a memory storage device multiple vehicle profiles, each saidprofile including multiple, independent vehicle-specific automatons;compute a GNSS-based guide path for the vehicle; determine variableconfidence levels in real-time for the GNSS-based sensor unit, the WAS,and the IMU sensor based on current relative performance of the sensorunits; use output signals from a first one of the sensor units with ahighest one of the confidence levels to provide output signals todetermine movements of the vehicle relative to the guide path; useoutput signals from the first one of the sensor units with the highestone of the confidence levels to calibrate a second one of the sensorunits with a lower one of the confidence levels; and provide outputsignals to a display device to display vehicle motion for the vehiclerelative to the guide path and to contrast displays of areas treated bythe vehicle along previously-traveled portions of the guide path.